Concrete pipe-forming machine, including means for extracting excess fluids by vacuum



Jan. 20, 1953 x. ESC'H BRENNER ,625,728

CLU G MEANS H. CONCRETE PIPE-FORMING HI IN FOR EXTRACTING EXCESS F DS BY UUM Filed Jan. 5, 1951 2 SHEETS-SHEET 2 r 65 INVENTORK jzczor l. Jae/1622576272262- ATTORNEY Patented Jan. 20, 1953 CONCRETE PIPE-FORMING MACHINE, IN- CLUDING MEANS FOR EXTRACTING EX- CESS FLUIDS BY VACUUM Hector X. Eschenbrenner, Columbus, Ohio Application January 5, 1951, Serial No. 204,551

6 Claims.

The present invention relates to apparatus for forming tubular cementitious bodies, and more specifically to a machine for producing concrete pipe sections. The present application is a continuation-in-part of my co-pending application Serial Number 767,928, filed August 11, 1947, entitled Method and Apparatus for Forming Concrete Pipe, now Patent No. 2,585,756.

In the ordinary type of concrete pipe-formingmachine, there is employed a substantially cylindrical and annular outer form, and a cylindrical inner core having a smooth surfaced outer wall disposed in substantially concentrically spaced relation to the inner wall of the outer form and defining therewith an elongated annular mix-receiving chamber into which a cementitious mix may be introduced to be molded into cylindrical pipe configuration. In such apparatus, there is generally also provided a rotary turntable and pallet upon which the outer form. is supported for rotation, with the pallet supporting the lower end of the column of cementitious mix. After the introduction of the mix within the annular chamber, the outer form, together with the mix, is rotated about the relatively stationary cylindrical inner core to churn and agitate the mix and consequently compact the same between the separate inner and outer forms of the machine. Upon completion of the rotation cycle, the inner core in generally removed longitudinally and axially of the outer form, leaving the preformed and plastic mix within the outer form and supported upon the pallet. Thereafter, the outer form, pallet, and preformed pipe are removed from the turntable and placed in a curing zone to solidify, while a second outer form and pallet are assembled upon the turntable for a successive pipe-forming operation.

In accordance with the invention disclosed in my co-pending application Serial Number 767,928, the inner core is provided with an internal vacuum chamber communicating with a multiplicity of perforations formed in the outer side wall of the core and opening into the mix-receiving chamber of the machine to subject a pipe-forming mix introduced within the chamber during rotation thereof to subatmospheric pressures to withdraw excess fluids from the mix. The use of vacuum pressures in connection with a concrete pipe-forming machine, as outlined in my co-pending application, enables what is known as a Wet mix, 1. e. a cementitious mix containing excess water, to be employed in replacement for the usual dry mix which requires the use of tamping apparatus to compact the mix vertically Within the pipe-forming chamber of the machine. It has been found highly advantageous to employ Wet mixes and thereby to eliminate the relatively complex and dangerous tamping apparatus associated with concrete pipe-forming machines employed in forming pipe sections from dry mixes.

While the prior art discloses the use of subatmospheric pressures in the withdrawal of excess fluids from cementitious bodies, so far as I am aware, previous methods and apparatus em ployed in this connection do not provide for the relative movement between the mix and the instrumentality by which the mix is subjected to subatmospheric pressures. Usually the mix is subjected to vacuum pressures by means of relatively stationary mats or plates having perforate 'areas through which subatmospheric pressures are applied to one surface of a mix remaining in situ.

In accordance with the present invention, I provide a concrete pipe-forming machine which incorporates the usual cylindrical outer iorm member and rotary turntable, but which employs an inner core memberformed to provide one or more vacuum chambers arranged to communicate with the mix-receiving chamber by way of a multiplicity of openings or perforations formed in the outer wall of the core to subject the mix to subatmospheric pressures during rotation thereof relative to the core. In combination with vacuum pressures, I further employ a plurality of mix-compacting rolls which are disposed longitudinally of the inner core and extend outwardly from the periphery of the inner core and into the mix-receiving chamber to directly engage a cementitious mix received therein and to compact the same outwardly against the outer form during rotation of the outer form and mix relative to the inner core, thereby to forcibly express excess fluids from the mix to facilitate the withdrawal of such excess fluids by vacuum pressures applied throught the inner core.

The primary object of the present invention is to provide a mechanically eflicient yet structurally simple apparatus of the aforesaid character which makes use of a number of elements common to the ordinary types of pipe-forming machines to thereby enable previous machines to be converted in accordance with the present invention without destroying or discarding the previous machines in their entireties.

It is another object of this invention to provide in a concrete pipe-forming machine an inner core member which is arranged to extend axially within an outer form member, such core member being formed internally with a vacuum manifold communicating with the pipe-forming chamber of the machine by Way of a number of perforations formed in the outer side wall of the core, and which, when the core is disposed in pipe-forming position, communicates with a suitable suction pump operable to produce subatmospheric pressures within the vacuum manifold and consequently at the perforations formed in the outer side wall of the core and communicating with the mix-receiving chamber, whereby, during rotation of the mix together with the outer form member, substantially the entire area of the mix is subjecteddo"subatmosphericpressuresto withdra 'excessifl iidsitherefrom.

Still a further object of this invention is to provide in a concrete pipe-forming machine an inner core member having an outer side wall formed at spaced intervals with airplurality of longitudinally extending slots "through which extend a like number of longitudinally disposed mix-compacting rolls, said rdlls being arranged to have a portion of their outerperipheral surface extending outwardly into'the mix-receiving chamber of the machine to directly engage a mix during rotation thereof around the inner lcore-lto rforcibly p.ack-the mix outwardly against .;1the,. inner.surface of the outer .form, and at the same time :to. express .excess fluids from the mix ;;to ifacilitate,withdrawalnfasuch fluids by vacuum gpressures.

fllhesel'and variousadditional lobiects and advantages .of :the invention will become .more :readily apparent by reference to the following description and the accompanying drawings, wherein:

1 is "a medial dongitudinal vertical secition'alview taken through a concrete pipe-forming machine according to the present invention;

Fig. 2 .is a horizontal sectional view taken along the rline 2-2 ofFi-g. 1;

Fig. :3 :is an enlarged fragmentary vertical sectional view taken along the line .3-3 of Fig. 2;

EJFignA vis :a side elevational view of the .inner core.

f-Referring1-now to the drawings, the numeral alfl designates generally .a supporting floor struciture-rwhichisrecessed .to provide a subterranean chamber .12. Advantageously, :the "walls of the floor defining the chamber 12 are stressed with metallic angle viron *frames 14, and .extending 'the :plane of "the 'bearing frame 20, and which communicate's ratits lower end with a remotely extending conduit '24 leading to and communieating *with the inlet side "of :a :suction pump 1 25. *The upper "surface "of the :bearing r'fra me :29 xseats an annular'thrust' bearing '2 6, and mounted upon'the upper 'suriaceof the bearing 26 is a irotary'andzgenerally circular "turntable 128. The turntable-28 is "provided axially with "an openiIIg 3.0 in-registration with the upper open end of the sleeve 2-2, and is "formed *at its outer marginal edge with 'an upwardly extending outer'flange "portion 32. The'under surface of "the rotaryturntable 28 is rigidly secured to an annular ring gear '34 whose teeth are disposed in "meshing engagement with a beveled pinion gear "36 .drivingly carried upon the horizontally 'disposeddrive'shaft 38-extending into the'cha'mher 12 below the upper level of the floor I0, and suitably connected at 'its opposite end with 7a driving "source, such as an electric motor, 'not fshown. The -shaft '38 is suitably journaled in 'bearingsflfl carried 'uponthe beams 16 and provides for'unifi'ed axial-rotation "of the annular ring gear 34 "and turntable '2'8.

"Mounted upon and rigidly "carried at spaced intervals ailong'the upper surface of the flange '32 of'the turntable are "a plurality of locking able clamping lugs 50.

'withthe outer form 46, and supported upon an section. In ftheiroperative positions, the separate sections of "the outer form it are joined to 20116 'ianother, as at 48, by means of detach- Carried in association inwardly extending annular flange 52, is an annular pallet 54 disposed at the lower end of the .outer form. The pallet 54 may advantageously beformed'instep-down cross-sectional configuration to ,provide .a reduced spigot end formation on a pipe section ,formed within the machine.

.Supportedin dependingrelation to .a vertically movable lifting shaft-.5 6 .as I by .mounting brackets 58, is a horizental top wall of a generally elongated -.and cylindrical inner .core 62. As shown particularly in .Fig. 4, the .core .62 comprises a cylindrical outer wall 6.4 which extends between .the upper wall and a lower .horizontally disposed head 66. The outer side wall lid of the core .is formed .at spaced intervals with longitudinally extending slots 168, and between the slotted areas of the outer-side wall, .thesame .is :formed with -a multiplicity of relatively small )periorate openings "iii. Provided upon the inner side of the wall 164 of the core, in the .plane :of .the slots -58, are a plurality of vertically aligned hearing sleeves 12 which rotatably support the relatively reduced end shafts 14 extending from the respective ends of a plurality of mix-compacting cylindrical rolls 15. The -rolls 1,6 are arranged in parallel relation to the .axis'of thecore :t.2,-and have asegment of their outer peripheral surface extending outwardly through the slots 68 of thecore beyond the outer surface :of the side wall '54. As shown in Fig. 1, when the inner core 62 is lowered into .its operative position, the outer side wall .64 of the core is disposed .in spaced concentric .relation to the inner side wall of the outer form 16, and defines with the outer form an elongated substantially cylindrical chamber 18 of annular cross-sectional configuration for the reception of 1a :cementitious 'pipe-iorming .mix fit. The inner side wall of the .coretfiz'is Iurther'provided with a plurality .of vertically extending halfround conduit sections 82 which are arranged in alignment with the vertically disposed per- ;forations "Hi "formed in the outer side wall 64 of the core. "The conduits 82 are preferably welded to the "inner side of the core and closed at their upper ends, as at 84, to provide a plurality of vacuum chambers 86 extending vertically within the core and communicating with the perforations 76. The separate chambers 86, at their lower ends, open freely into a manifold chamber 88 formed internally of the lower head section '65 of the inner core. Extending axially and downwardly from the lower head section "66 is a tubular extension 99 having a bore 92 communicating with the chamber 88 of the head section. As will be seen from Fig. "l, the pipe extension 90 is arranged in vertical alignment with the sleeve 22, and as the core is lowered to its operative position, the extension "90 enters the sleeve 22 and seats against 'a'packing ring at to provide a fluid-tight slipfit connection therewith. -In the position shown in Fig. 1, the pump 25 creates a suction through the conduit 24, the sleeve 22, the bore 92, the manifold chamber 88, and within the individual conduits 82. Advantageously, there is interposed between the lower surface of the head 66 of the core and the upper surface of the turntable 28 a second annular thrust bearing 96 which prevents friction and rubbing between the turntable and the under surface of the core. It will also be noted that the outer diameter of the head 66 is substantially larger than the diameter of the outer wall 64 of the core, and corresponds substantially identically to the outer diameter defined by the outer peripheries of the mix-compacting rolls 1 6. In this manner, the lower head 66 functions as a troweling skirt upon upward movement of the core axially with respect to the mix 80 after the same has been initially preformed to pipe configuration; Such upward movement smooths and trowels the inner wall surface of the mix to remove any irregularities formed thereon during rotation of the mix and compacting thereof by the rolls 16.

In operation, the outer form 46 is assembled into cylindrical formation, with the pallet 54 positioned within the lower end thereof, and in such assembled form is positioned upon the upwardly extending flange 32 of the turntable and locked thereon by the cleats 42. Next, the inner core 62 is lowered from an originally elevated position axially within the outer form 45 to its position as shown in Fig. l, with the pipe extension 90 extending within the vacuum socket 22. In this position, the inner and outer forms are ready to receive the wet mix 80 which is introduced within the upper end of the annular pipe-forming chamber 18 by way of a hopper chute 98. As the introduction of the mix within the chamber is initiated, the drive shaft 33 is driven to rotate the turntable 28 and the outer form 45 and pallet 54. Thus, as the mix gravitates downwardly from the chute 98, the same is dispersed evenly around the pipe-forming chamber and is rotated relative to the compacting rolls until the mix 80 reaches the upper level of the outer form 45. Rotation is continued and the pump 25 energized to create subatmospheric pressures at the outer surface of the inner core. As the mix 80 rotates relative to the compacting rolls 15, the same is churned and compacted outwardly against the inner surface of the outer form 45, and this compacting action expresses and squeezes excess fluids. both water and air, from the mix into the space between the inner surface of the mix and the outer side wall 64 of the core to be drawn oif through the perforations 70, the conduits 82,

'the manifold.88, and outwardly through the pump 25. Rotation of the outer form, together with the application of vacuum pressures, is continued for a predetermined time to remove all excess fluids from the mix, after which rotation is discontinued and the pump 25 deenergized. The inner core 62 is then elevated and the outer skirt region of the lower head 65 of the core moves in wiping engagement with the inner side surface of the mix Bil to smooth and trowel the surface as the same passes axially outwardly from the mix. Thereafter, the cleats 42 of the turntable are disengaged from the outer form 46, and the latter, together with the pallet 54 and the plastic mix 80, is lifted from the turntable and disposed in av remote curing zone where the mix is permitted to dry to its final rigid form prior to the removal of the sectional outer form 46.

In View of the foregoing, it will be seen that the present invention provides an eiiioient machine for forming concrete pipe sections and similar tubular bodies from an initially wet and fluid cementitious mix which is easily handled and poured into the pipe-forming chamber without requiring tamping or vibration to initially compact the raw mix as is the case with dry mixes. Further, in utilizing the cylindrical expression rolls to engage and squeeze the wet mix against a form member during relative rotational movement of the mix and the rolls, substantially all excess fluids are extracted or expressed from the mix while the same is churned and compacted into pipe formation. The application of subatmospheric pressures to the pipe-forming chamber of the machine serves to carry off the excess fluids expressed from the mix by contact with the compacting rolls. A further advantage ambient to the invention stems from the fact that the invention lends itself for use in connection with component parts or elements of the ordinary pipe-forming machine, and can be adapted to such machines without extensive modification thereof and with relatively little cost.

While a single preferred embodiment of the invention has been disclosed in detail, it will be understood that various modifications may be resorted to without departing from the spirit of the invention or the scope of the following claims. It will also be understood that the invention comprehends broadly the relative rotation between the cementitious mix and the compacting rolls, and that it is possible to rotate either the mix about the rolls or the rolls about the mix, or both, as a particular application may warrant, without changing the scope of the invention.

I claim:

1. A machine for forming tubular cementitious bodies comprising a cylindrical outer form; a cylindrical inner core movable axially of said outer form and having an outer side wall disposed in concentrically spaced relation to said outer form and defining therewith an annular chamber for the reception of a cementitious mix; a plurality of mix-compacting rolls journaled in said inner core and extending longitudinally thereof, said rolls being arranged in relatively spaced parallel order about the periphery of said inner core and projecting slightly outwardly into the annular chamber formed between said outer form and said inner core for direct engagement with a mix introduced within said chamber, the outer wall of said core between said rolls being formed with a plurality of openings communicating with the mix-receiving chamber; means in said inner core defining a substantially enclosed chamber in communication with the openings formed in said core; means for establishing subatmospheric pressures within said last-named chamber and at the openings formed in the outside wall of said core; and means for imparting axial rotation to said outer form and to a mix received in the mix-receiving chamber, whereby to circulate such a mix around said inner core and relative to the openings formed in said inner core, said rolls serving, during rotation of said mix, to compact the same against the inner side wall of said outer form and to express from said mix excess fluids present therein, the openserving to :carry 701T excess fluids-expressed from isaid mix by said rolls.

. 4-2. ,In a'concretepipe-forming machine; an annularouterform; acylindrical inner corelhaving ':a perforate outer side wall positioned in spaced concentric relation to said outer form "and defining'therewith an 'annular chamber for .Wardl-y through the recesses .formed. in the outer :walliof said core for direct engagement with a mixlrecei-ved in saidannular chamber, said rolls extending substantially throughout the length of said core; and-means,forrotatingsaid outer "formand La mixtreceivedin said chamberrelative to said inner core and said rolls, whereby 'to .cause said mix to be compacted against said outer form'by engagement with said rolls and thereby to express excess fluids present in the mix outwardly therefrom for withdrawal through the perforations in said core.

-3.-In a machine for forming concrete pipe; in combination, an elongated annular outer-form; a cylindrical inner core having an outer side wall formed with a plurality "of peripherally spaced longitudinally disposed recesses and disposed in spaced concentric relation to the inner wall of said outer form and defining therewith an annular pipe-forming chamber for the reception of a cementitious'mix, said core being provided with a multiplicity of perforations extending through the outer side wall thereof; means for axiallyrotating saidvouter form and a mix introduced within said chamber about said innercore; and a plurality of elongated cylindrical mixcompacting rollsjournaled in and extending longitudinally of and substantially coextensive with .saidcore and having a portion of their outer periphery extending outwardly through the recesses formed in the outer side wall of said core and into said pipe-forming chamber for direct engagement with a mix received in said chamber, saidrollsserving, upon rotation of said outer form, .to compact a mix received in said chamber throughout substantially the entire length thereof and to force the same outwardly against the inner ,side wall .of saidtouter :form, and thereby to express-excess fluids present in said mix outwardly therefrom for withdrawal by way of the perforations provided in said core.

.4. In apparatus for vmaking concrete pipe; .a horizontally disposed rotary turntable; a substantially vertically arranged hollow cylindrical outer form supported .at its lower end by said turntable; a cylindrical inner core having a longitudinally slotted outer side wall disposed in spaced concentric relation within said outer form and defining with said outer form an elongated vertically arranged chamber of annular crosssection for the reception of a pipe-forming mix, the outer wall of said core between the slotted regions thereof being formed with perforations; means carried by said outer form for closing the lower end of said chamber; means drivingly connected with said turntable for imparting axial rotation to'said turntable and to said outer form; a plurality of elongated cylindrical mix-compactingzrolls journaledin peripherally spacedre- -means for -lation on said inner core and having their axes disposed-in parallel relation .to the axis of said inner-core, anda portion of their peripheralsurface extending outwardly and longitudinally of the slots formed in the outer wall of said core for direct engagement with a mix received within said chamber, saidrolls serving, upon rotation of said outer form, to compact a mix received within said chamber against said outer form and to express from said mix excess fluids present therein; manifolding means disposed within said core and communicating with the perforations formed in the outer side wall of said core; and means communicating with said .manifolding establishing subatmospheric pressures .within said manifolding means .and at the perforations formed .in the outer side wall of said core to withdraw excess .fiuids from acmix received .in said chamber byway of the perforations and said manifolding means.

5. In a machine for forming concretepipe; a pair .of concentrically spaced cylindrical forms defining an annular pipe-forming chamber for the reception of a wet cementitious mix, at least one of said forms being perforate; means to rotate one of said forms relative to the other; and a plurality of cylindrical mix-compacting rolls journaled in one of said forms and arranged in parallel relation to theaxes of saidlforms, said rolls being substantially coextensive with the length of said chamber and having a portion at least of their outer peripheral surfaces projecting into said pipe-forming chamber for direct engagement with a cementitious mix introduced therein and being operable during relative rotation of said forms to express fluids from such mix for withdrawal through the perforations in said one of said forms and to compact the mix radially against the opposite form.

6. In a machine forforming concrete pipe; a pair of concentrically spaced cylindrical forms defining an annular pipe-forming chamber for the receptionof a wet cementitious mix, at least one of said forms having a perforate wall surface adjacent said chamber; means to rotate one of said forms relative to the other; a plurality of cylindrical mix-compacting rolls journaled in one of said forms and arranged in parallel relation to the axes of said forms, said rolls being substantially coextensive with the length of said chamber and having a portion at least of their outer peripheral surfaces projecting into said pipe-forming chamber for direct engagement with a cementitious mix introduced therein and being operable during relative rotation of said forms to express fluids from such mix and to compact the mix against the opposite form; and means communicating with said pipe-forming chamber byway of the perforations in said one of said forms for creating subatmospheric pressures within said chamber adjacent one of said forms and for withdrawing fluids expressed from a cementitious mix by said rolls.

HECTOR X. ESCHENBRENNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1;750;748 Edmunds Mar. 18, 1930 1,938,230 Ukropina Dec. 5, I933 979,415 Soso Nov. 6, 1934 2369,608 fSalvaneschi Feb. '13, 1945 

